Its likely that Sheldon is still privy to Pinetree's current situation in terms of how many POET shares they have remaining and feels this is the right moment to start purchasing. Why would he start any earlier knowing that Pinetree would continue adding pressure for the forseeable future. This gets him closer to the best price and knew this would create an amazing buying opportunity. I try not to speculate on these sorts of things, but it totally makes sense when you combine the buying by anonymous today with the numbers TWG provided today and some of the other theories floating around here today.
This could be a very positive sign for those that are looking for a bottom. Regardless everything is lining up for a rebound within the next few weeks and more than likely starting mid next week (approx. 3 days before the end of the month) for the next NAV update.